Wednesday, November 27, 2019

We ignore science, including the study of insects, at our own peril. This was an underlying message in session after session of the 2019 Annual Conference of the Entomological Society of America.

This year's ESA conference, just a few minutes' walk from the iconic St. Louis Arch, was my first business visit to the the city where I spent most of my growing up years. Out for a jog on the first day of the meeting I remembered as a kid watching workers fit last shiny aluminum triangle into place at the top of the Arch shortly after my family arrived. I admit I felt a little old when I realized the Arch turned 55 this year.

Glorious flies

As glorious as technology can appear to the human eye, I was quickly reminded that insects are just as cool, and have been around a lot longer than any arch. The plenary session speaker was Janet McAlister, British author of the book The Secret Life of Flies. With a generous dash of humor, McAlister breezed through story after story of amazing flies. One in ten living species on the planet is a fly, she said, with 17 million individual flies for every living human. Flies are also beautiful when you get close enough.

We can thank the fruit fly, Drosophila melanogaster, a pest of kitchens and hospitals around the country, for its contributions to our modern understanding of genetics and the genes associated with diseases like Alzheimer's and Parkinson's.

Flies are important pollinators too. A type of biting midge is also the sole pollinator of Theobroma cacao, our plant source for chocolate. No flies? No more chocolate.

And as McAlister pointed out, at times even crime fighters depend on flies. The first murder solved with the assistance of insects was the strange case of Dr. Buck Ruxton in England in 1935. Ruxton was convicted of murdering his wife and servant after the fly maggots found in his victims' decaying bodies were used to estimate the approximate time of the murder. And as any fan of television's CSI shows will tell you, flies are used for the same purpose today. For some fantastic images of flies, check out Gil Wizen's photography page (featured in many of McAlister's slides).

The coming Insect Apocalypse?

It's not too often that I see reference made to the Bible in a scientific paper, much less a meeting; but this year's buzz-phrase for many attendees was "insect apocalypse." One of the better attended symposia was devoted to Insect Decline in the Anthropocene (the Anthropocene is a scientific term for the man-dominated biological/geological era we are in today). While I missed several talks in this session while darting between papers, the central message was clear. Something is happening to insect populations around the world, and it's not good.

Among concerns of attendees are declines in many kinds of
wild bees, sometimes referred to as a "Beepocalypse"

Hans deKroon, from Radboud University in the Netherlands reported on the results of a 27 year study of insect densities in 63 German nature preserves. Using the same sampling method and places for sampling in relatively unchanged parklands between 1989 and 2016, the researchers documented a 76% decline in the total weight of insects (biomass) caught in traps over this time. The surprising thing was that declines were seen across all sites with all kinds of insects--not just a few. The authors attribute some of the decline to land fragmentation (sites were often close to agricultural land), but also possibly pesticides and climate change.

David Wagner, University of Connecticut, reported a similar 70% decline in moths of pristine New England forests. The decline, he said, averages 1-2% per year and is across a large region. The only explanation is some kind of broad external cause(s). Beyond increasing global temperatures, possible causes for loss of moths and butterflies include nitrification, light pollution, exotic insects, and car strikes.

So what are the consequences of such large declines in insect biomass? I mean shouldn't we be rejoicing in fewer insects if this means fewer pests? Absolutely not. In addition to entomologists, all sorts of biologists and nature lovers should be concerned by these numbers. Insects are keystone (ecologically very important) species in many environments. They help decompose dead organic matter, keep potentially invasive plants under control, and feed fish and birds and many, many other types of wildlife. Indeed, one especially depressing study in the Science journal this year reports a 29% decline in bird numbers in the U.S. since 1970 (click here to see the paper in full). While the reasons for bird decline are complex, losing an important food source is not good for birds or bird lovers.

Tim Showalter, Louisiana State University, cautioned attendees to take care in drawing hasty conclusions, and in careless interpretation of apocalyptic data. In a cautionary paper, he noted that a 2018 paper on supposed food chain collapse and a 60% decline in insect populations due to climate change in a Puerto Rican rain-forest garnered attention in the press, but was ultimately based on faulty data. A change in positioning of temperature stations, misinterpretation of different survey databases, and impacts of multiple hurricanes led the authors to erroneous conclusions. The food chain is NOT collapsing in Luquillo, Puerto Rico, he said. A rebuttal to the paper is now posted on the journal website.

Showalter's paper illustrates the imperfection, yet self-correcting nature of science. It also illustrates how easy it can be for interpreters of science to cherry-pick data to reinforce a given point of view. We all need to be critical readers of science; however, this doesn't mean we can't trust scientists. Certainly the majority view of entomologists is that something alarming is happening to many kinds of insects in many locations around the world. We should not ignore this issue or the scientists raising fair warning.

Learning from History

Rocky Mountain locust, Melanoplus
spretus, ca. 1870s, Minnesota.

As I get older, history gets more interesting. The ESA is fortunate to have among its membership a significant number of scientists with an interest in the historical roots of entomology. For example, I learned from Jeffrey Lockwood, University of Wyoming, that the first recorded time our government called on science to solve a political problem involved entomology. Between 1874 and 1877 the Rocky Mountain locust caused staggering crop damage in Kansas, Nebraska, Minnesota and Missouri. While inventors and hucksters of the day promoted a variety of solutions for locusts, little was really known about the biology and life cycles of these insects. For example, many farmers believed that locusts were so diabolically destructive because they were led by kings and queens (not true).

In 1876 a new governmental group known as the Entomological Commission was authorized by Congress to study the problem. The team quickly recognized that the key to the locust's destruction lay in identifying its true identity, its breeding grounds and the conditions that led to outbreaks (sounds a lot like an IPM program). Also a collection of natural enemies was identified. While this information would have ultimately been useful in developing long-term control measures, Rocky Mountain locust swarms were already in decline by 1877--something for which the entomologists were happy to take credit. It turns out that by the 1880s the swarms all but ceased, likely because of the loss of the great buffalo herds which, by reducing food in the permanent breeding range, and pulverizing the soil with their hooves, would trigger the buildup of migratory locust swarms.

Entomologists were pragmatists in the locust wars, arguing against those who ascribed the swarms as evidence of God's judgement due to a general lack of morality and repentance. Rather than promoting a day of prayer, however, entomologists insisted that farmers would be better served by looking to science to discover the causes and solutions to the plagues. Today the Rocky Mountain locust is extinct, following the path of all organisms that cannot adapt to a changing environment.

Insects and Health

Like it or not insects are important factors in human health. Insects and indoor health was the theme of one session I attended. Respected researcher Felicia Rabito, Tulane University, pointed out that asthma remains relatively poorly understood, despite its public health significance. One in 12 children in the U.S. suffer from asthma, a chronic inflammatory disease of the airways. In her studies 73% of homes have elevated levels of one or more environmental triggers of asthma (e.g., smoke, pet dander, particulate air pollution, and pest derived allergens). Cockroach allergens remain one of the strongest promoters and triggers, and appear to cause four times the hospitalization rate of other allergens. Her research with a relatively small sample size showed that even a single IPM intervention (bait only) could have significant positive health outcomes for kids living in treated homes. Their team plans to redo the study with a larger (300 household) sample size.

A co-researcher with Rabito, and one of the most original and thought-provoking urban entomologists today, Coby Schal, North Carolina State University, gave an interesting talk on reducing cockroach allergens simply through cockroaches baiting. He argued that the comprehensive IPM approach, such as advocated by the National Institute of Allergy and Infectious Disease, starting with improving sanitation, use of non-chemical tactics, biological control and (perhaps) chemical control may be too slow and expensive in most cockroach infested homes (think public housing). His data suggests that IPM and health specialists should lead with cockroach baiting because it is the fastest and least expensive way to reduce indoor allergens. It remains alarming to me the number of pest control companies that still rely primarily on sprays to control German cockroaches, when baits have time and again been shown more effective in controlling cockroaches and improving public health.

Bed bugs remain a topic of interest in these meetings, though not to the level of 5-10 years ago. Jonathan Sheele gave two papers on bed bugs from a doctor's perspective. In the Ohio Emergency Room where he previously worked, he noted that when bed bugs were found on a patient, that room would be out of use for cleaning and pest control an average of 20 hours. This would happen every 2-3 days on average. His hospital spent $30,000 annually on IPM costs associated with infested patients. Patients with bed bugs were more likely to suffer anemia, Staphylococcus infection, and use an inhaler than patients without bed bugs. In a separate paper, Sheele reflected on the potential for a future pill that people could take to kill bed bugs. In lab studies, both spinosad and fluralaner (Bravecta®) provided excellent control of bed bugs; however neither drug is yet approved for use on humans. Abamectin is another antiparasitic agent that does have human approval, however tests on its effectiveness in humans against bed bugs have not been conducted. Such an innovation could be a big boon, especially for low income families suffering from bed bugs.

Stephane Perron, National Institute of Public Health in Quebec, Canada, looked at bed bugs in public health and reported that bed bug infestations often result in prolonged stress for patients. Some of the mental health impacts of bed bugs include fear, sense of lack of control, physical discomfort, sleep deprivation, financial stress, property loss, stress over preparing a home for treatment, conflicts with neighbors, the stigma associated with bed bugs, fear of insecticides, and exacerbation of prior mental health issues. On the flip side, a recent study she conducted showed that anxiety and depression could decline when bed bugs were successfully controlled--a real benefit pest management companies can take pride in.

Zach DeVries, University of Kentucky, noted that the bed bug's status as only "a nuisance" is coming to an end. Again, public health professionals, decision makers and politicians need to take cockroaches, bed bugs, mosquitoes and other urban pests seriously.

Odds and Ends

Again I felt a little old during this meeting when I realized how different students are today. Grad students at the meeting are more diverse and more attuned to social media than ever before. As such they represent many of your younger pest control customers.

Striving to keep up, I attended a session on using social media. I found myself in a group fellow laggards who did not understand some of the basics of the Twitter platform. While I do use Twitter (@mikemerchant), I realized I still didn't understand some of the basics of the app and Twitter platform. I learned how to better use hashtags, and that I need to follow more people if I want to expand my personal Twitterverse (I have a difficult-enough time with the regular Universe) #oldfashioned, #luddite, #booklover. I reflected that if we fail to learn from these young professionals we risk ending up like the Rocky Mountain locust.

Joe DeMark, Corteva AgriScience, gave a paper on a new termiticide caulk formulation in the works. The caulk provides another above-ground option for treating termite tubes. It could, I envision, replace the somewhat clunky (though effective) AG bait stations. Caulk has an advantage of being flexible enough to inject into infested trees, or placed directly on an exposed termite foraging tube. It has the same active ingredient as Sentricon, noviflumuron and is applied with a regular caulk gun. In studies conducted in New Orleans against Formosan termites, tree infestations were consistently eliminated in about 2.5 months. Control of termites in homes was accomplished in 30-90 days. If it should ever become a product, DeMark does not expect
it to be commercially available until after 2020.

The Asian longhorn tick is now present in 11 states since its discovery in 2017. A first human bite was recorded this year, which was significant because of its ability in other countries to carry disease to both livestock and humans. In a talk by Ryan Smith, Iowa State University, I learned that a 2019 study showed that the tick could pick up Lyme disease from an infected mouse (bad). But the same study showed it could not maintain the disease through molting. This is good news, because it means this tick is unlikely to transmit Lyme disease in the wild. Nevertheless, there are other diseases of concern and the increasing number of exotic pests being introduced into the U.S. continues to threaten both ecological and human health

Lastly, the ACE Associate Certified Entomologist program hosted by the ESA continues to grow. As of this writing there are 1251 active ACEs. ESA estimates that there will be 1,272 ACEs by the end of year (lots of new applicants currently), representing 13.5% growth since December last year. The ACE program is unique in that it is the only individual-oriented certification program. It can provide potential customers with assurance that your company has qualified staff, and allows you to attend meetings like the St. Louis conference at discounted rates.

If you think you're interested in becoming an ACE, check out the ESA Certification Corporation website. And consider attending one of the upcoming Texas prep classes in Dallas or in College Station. The class is an excellent way to either begin studying, or as a last-minute confidence builder before taking the test.

Each of us has a unique role to play in service to our society. But we only do our jobs well when we commit ourselves to lifelong learning. As is clear from these meetings, knowledge is expanding rapidly. I hope each of you keep following the science behind the pest control profession (as you already are by reading to the end of this post) and continue to avoid the perils of unfounded opinion.Science is the father of knowledge, but opinion breeds ignorance. Hippocrates

Monday, October 28, 2019

The past week I've been speaking to PMPs at CEU conferences about the emerald ash borer. Many folks have asked why they've never heard about this pest. I guess that's because it's a relative newcomer to the state and its impact is just beginning to be felt.

If you are one of the many in our industry who has heard little or nothing about this insect, let me enlighten you. The emerald ash borer, Agrilus planipennis (EAB), is a wood boring beetle that attacks trees in the genus Fraxinus, which we know as ash. Since it was first discovered in SE Michigan in 2002 it has spread with alarming speed throughout the midwest. In 2017 the first beetle was found in east Texas.

The EAB is probably the most devastating forest pest since chestnut blight. In areas where it has been in place for 10+ years it has virtually wiped out every ash tree. Some fear that certain ash species may be on the edge of extinction thanks to the borer. We have every reason to think the same thing will happen in Texas.

Ash is not as common in Texas compared to Michigan and other parts of the Midwest; but it is an important tree, especially in areas along streams and river bottoms. And it's a very important tree if you have one in your backyard.

Not every one of you provide lawn or tree care services, but if you do you should keep your eye on this beetle. Even if you don't "do trees" you can still provide a service to your customer by alerting them to the risk of this beetle if they have ash trees on their property.

Emamectin benzoate is an effectivetreatment applied by certified applicators.

Currently, EAB has been found in Marion, Cass, and Harrison counties in far east Texas. Most recently a well-established infestation of the borers has been found in west Tarrant county, just a few miles to the northwest of Fort Worth. Anyone who cares for an ash tree who lives within 15 miles of a known infestation should consider their trees at risk (this includes most homes in Fort Worth), and should consider having it treated.

A handful of insecticides can provide protection of an ash tree at reasonable cost. If you are interested in being on the leading edge of how to treat ash trees for EAB in Texas, there are three workshops coming up, sponsored by the Rainbow Treecare company (Rainbow makes one of the leading insecticides for EAB management). Two of the workshops focus on community EAB management strategies, and one will provide a general introduction to EAB.

These workshops are webinars. If you've never attended a webinar, it's a pretty cool, and easy, way to learn. You sit at home or in your office, link up to a website, and watch and listen. You will also have the chance to submit questions and interact with the speakers. To read about the webinars and register, go to https://register.gotowebinar.com/register/2236702821873051149

I hope to write more about this beetle in the future. In the meantime, get out your tree books and read up on ash. Once you learn to distinguish ash you will be able to tell whether a customer's tree is at risk.

Friday, October 25, 2019

Paper wasps are common throughout Texas, frequently nesting
in windows and under house eaves. With the advent of cold
weather, many of these wasps will head indoors.

Years ago, a friend described a memorable pest control experience that still makes me chuckle. It was winter, and she had noticed a few wasps flying around her immaculate home. So naturally she called her pest control company. Her technician arrived and noticed a wasp on the fireplace. When he opened the chimney flue to investigate, to his (and her) horror a large ball of paper wasps fell from the flue into his lap. He turned to my friend, fear in his eyes, and yelled, “LADY, GRAB YOUR BABY AND GET OUT OF THE HOUSE!”

I don’t recall how long it took them both to recover their wits and clear out the wasps; but if the PMP had known a little more about paper wasp biology and behavior he could have displayed more finesse and saved his customer an unnecessary fright.

Paper wasps are one of many insects that enter homes and other buildings during the fall and winter. Like paper wasps, many insects protect themselves from cold by instinctively seeking shelter in trees, natural rock formations and (in towns) buildings. This leads to a number of insects that are seen indoors only during the winter months. It’s important to realize what’s going on and how to recognize these often-interesting invaders when they show up in your account.

Polistes wasps

Take my friend’s wasps. Paper wasps are the most common form of wasp in most Texas towns. The come in different colors and go by different names (e.g., red wasps, hornets, umbrella wasps); but all belong to the same wasp genus, Polistes. During summer months they can be recognized by their umbrella-like, paper nests that hang under eaves of houses, in sheds, and in trees. Polistes wasps do not enclose their nests with a paper envelope like hornets or yellowjackets; but they will sting anyone who gets too close or disturbs their nest. Every fall they exchange their paper nests for locations where they will be protected from ice and winter storms. Preferred sites are high points like chimneys, multifloored office buildings and towers.

Box elder bugs may enter homes in late
summer by the hundreds.

Unlike summer-active wasps, overwintering paper wasps show little or no aggression. Without a nest to defend, wasps simply lack the instinct to sting. A fly swatter or vacuum are all that is needed to dispatch wasps safely. If my friend’s PMP had calmly put down his lapful of wasps and asked for the vacuum cleaner, no babies need have been evacuated.

Box Elder and Red-Shouldered Bugs

Box elder and red-shouldered bugs (Boisea trivittata and Jadera haematoloma) are true bugs that feed on seeds of certain trees. They often become pests in later summer and fall when they seek protection from cold weather. To them, buildings must resemble big hollow trees, similar to what they would use for shelter in the woods. Control these insects by sealing doors and making sure window screens are tight and in good repair. Neither insect is damaging to the trees they feed on and they are mainly nuisances when they come indoors. During the summer box elder bugs will be found on box elder and maple trees. Red-shouldered bugs are feeders on soapberry, Chinaberry, golden raintree and other trees in the soapberry family.

Nipplegall Makers

The hackberry nipplegall maker (Pachypsylla
celtidismamma) is common in homes, especially
where there is a nearby hackberry tree.

Hackberry nipplegall makers are common wherever hackberry trees grow throughout Texas. These tiny (2 mm-long) insects are small enough to get through most window screens and any small openings in buildings. In the summer these insects form nipple-shaped galls on the leaves of hackberry and sugarberry trees. When they emerge by the thousands from their leafy homes in late summer they are commonly found indoors and especially around windowsills. The good news is that hackberry nipple-gall insects are pretty harmless. They do not bite, do not eat clothes and are a pest only because we don’t like little bugs in our homes.

Multicolored Asian Lady Beetles

The multicolored Asian lady beetle
(Harmonia axyridis) has become a common
fall indoor pest in Texas homes.

One of the most annoying of the fall invader insects are multicolored Asian lady beetles. These large lady beetles are natives to China and have been causing homeowners headaches since the early 1990s when they first appeared in Texas. In their native Asian home, these lady beetles move into crevices in limestone bluffs in the fall. In the U.S. they are more likely to move into light-colored homes and buildings in wooded areas where the beetles feast on aphids during the summer. Caulking and sealing along roof lines and vacuuming up the (sometimes large) aggregations of beetles where they cluster indoors or in attics is the best solution.

Cricket Hunter Wasps

The Texas cricket hunter wasp may be
one of the least well-known household
pests in Texas.

Maybe the least widely recognized fall invader is what I call the Texas cricket hunter wasp. These medium-sized (1/2 inch), black wasps with dark wings can be found year-round but are most common indoors during warm days in the winter and spring. They are commonly seen actively climbing up and down walls of bathrooms and other living areas. So, what are these wasps doing in homes? In nature, female cricket-hunter wasps establish nest sites in holes in the ground, such as rodent burrows, and provision those holes with fresh crickets for their offspring. In urban areas the wasps substitute weep holes and cracks in soil under building foundations for nest sites. Hundreds or possibly thousands of crickets may be stashed under homes or in walls. During periods of warm weather, the wasps’ offspring that have fed on these dead crickets can emerge indoors in large numbers. For more information on these wasps, and how to deal with infestations, check out my online factsheet.

Wintertime may be slower for the pest control business in Texas, but there are still plenty of pests out there. It’s a sign of a true pest control professional to be familiar with the less commonly encountered pests--don’t be caught off-guard when that next winter pest challenge drops in your lap.

Friday, September 20, 2019

Just a quick post to let readers know about a couple of pest control classes coming up soon, one in Dallas and one in Austin.

Dr. Bob Davis, BASF, has been teaching ACE Prep Classes
for more than ten years. I guarantee this will be one of the
best training classes you will attend this year.

On September 25 we still have room in our first Bed Bug Academy at the IPM Experience House in Dallas. The class will cover basic bed bug biology and state of the art information on monitoring and control. The class will be taught by Mr. Alan Brown of ABC Home and Commercial Services in Austin, and myself. It's an all day class (8:15 am to 5 pm) with CEUs and verifiable training hours for apprentices. Cost is only $60 preregistration. Class size is limited, so don't procrastinate. Registration, agenda, map and more information can be found at https://agriliferegister.tamu.edu/productListingDetails/2913

For anyone who has considered becoming an Associate Certified Entomologist, ABC Home and Commercial Services in Austin is hosting an ACE Prep Class on October 1. I've talked about this class in the past on Insects in the City blog, but if you are unfamiliar, this is a chance to either inspire your study or to do some last minute cramming before the test. Even if you're not sure whether you want to be an ACE, the class provides an excellent overview of the technical side of being a pest management professional. Led by Randy McCarty, myself and Dr. Bob Davis, this will be an intense but fun class. Best of all, there is no charge! To get in there is no fancy registration, simply contact Randy McCarty and let him know you would like to attend (rmccarty@goanteater.com, 512-534-5772). The class will run from 8 am to 4 pm and will be held at ABC Home and Commercial Services office, 9475 East Highway 290, Austin, TX 78724. Parking on the left side of building.

Remember you can never stop learning. The day you stop learning you might as well hang it up.

According to his daughter, Mr. Marrable was found by staff last week covered with ants. Even worse, family wasn't notified by the hospital after the attack. His daughter learned of the incident only after inquiring about the red bumps on her father's body. Although Mr. Marrable's death has not been directly blamed on fire ants, the incident was traumatizing to all involved.

This story would be more shocking to me, except I have been involved in at least two lawsuits where fire ants attacked patients unable to respond or call for help. And despite the fact that stinging cases are often hushed up, many other incidents occur every year.

It doesn't have to be this way. Fire ants are highly manageable given our scientific understanding of fire ants, and today's pesticide tools. But fire ant management always requires attention to detail. It also requires cooperation and communication between the health care facility and its pest control provider.

If your company provides pest control for health care facilities, here are some essential elements needed to keep your customer (and you) out of the headlines.

Ensure the facility has a policyregarding indoor ants. The plan should include clear staff instructions on how to immediately report signs of ants to your company.

Be sure your staff is always updated on what wings/rooms house high-risk patients.

Require patients to be immediately removed from any room with ants to another ant-free location. In this Georgia incident, the patient was returned to his original room only to have fire ants return and attack again a second day. No patient should be returned to an infested room until the indoor and outdoor areas around the room have been inspected, treated and cleared by a pest control professional.

Clean infested rooms with a soap solution and disinfect before allowing any patient to return. Holes and suspected ant entry points should be either sealed or treated. Cleaning with soap removes traces of trail pheromone that might lure other ants back into the room.

Conduct periodic staff training classes to let nurses and other caregivers know how to identify fire ants. In this week's incident it is telling that none of the staff interviewed referred to the ants as fire ants, only "ants." Fire ants pose perhaps the greatest immediate health threat to aphasic patients, and should not be difficult to recognize with training.

Inspect outdoor areas regularly for fire ants, and train maintenance staff to recognize and report evidence of fire ant nesting around the facility.

Fire ant infestations inside a building can almost always be traced back to a fire ant mound or colony outdoors. It's important to know who is responsible for grounds treatment ahead of time. When one contractor is assigned duty for indoor pest control and another for outdoor pest control, blame-shifting is inevitable. The losers in this game are the patients. Ideally, one contractor should be responsible for both indoor and outdoor fire ant control, so there is no confusion.

Don't rely solely on mound treatments for fire ant control. Broadcast applications of either baits or residual insecticides are always a better option. Fire ant baits are ideal for large turf areas and are typically applied once or twice a year. Residual granular insecticides containing fipronil or bifenthrin can be used annually in landscape areas immediately adjacent to buildings. The idea is to keep fire ant mounds as far away from the building as possible. Fire ant control should start at the property line, not the final two feet to the building.

Don't allow unlicensed applicators to apply insecticides for fire ants. In Texas, pest
control at health care facilities must be performed by a licensed pest control technician or certified applicator. This includes control of ants and other insects, pest birds, plant diseases, rodents, and weeds.

Document everything you do in writing on your service report. Document both pesticide and non-pesticide-related actions taken during the visit. Be specific about what pests are found during inspections. Remember, there is no such thing as just an "ant." Fire ants should be clearly identified. Assume that any of your service tickets could be examined by a lawyer some day.

If doing pest control around nursing home facilities sounds risky, it is. But a conscientious company can succeed at this business. And a nursing home can be one of the most rewarding accounts you have. As a friend and colleague points out, the biggest risks happen with "low-bid contractors who are not willing to address underlying problems."

Mr. Marrable's daughter told the Washington Post that her father "deserved better" than the treatment he received in his last days. Let's make sure all our sensitive accounts, like nursing homes, get the good service they deserve.

Friday, August 9, 2019

If it seems you're hearing less about West Nile virus (WNV) this summer, you may not be imagining it. Although mosquitoes have been abundant in north Texas this year, for some reason the virus has remained relatively quiet.

Where has WNV gone?

A paper written by epidemiologist Dr. Wendy Chung and colleagues in 2013 may offer some insights on the absence of the virus this summer. Those of us who lived in Dallas in 2012 may remember that summer as the worst human outbreak of WNV ever. Nearly 400 cases were reported in Dallas County alone, and 19 people died of the disease. The epidemic was so bad that Dallas county resorted to spraying the entire county for mosquitoes by plane--something not seen in north Texas since an encephalitis outbreak in 1966.

Chung and colleagues charted the course of the disease during 2012 and saw high infection rates of mosquitoes early in the summer, followed by a rapid increase in human cases. Looking back over previous years and case numbers, the researchers concluded that an unusually mild winter followed by rainfall patterns ideal for mosquito breeding in the spring (and a very hot summer--West Nile virus multiplies quickly in mosquitoes at higher temperatures) created ideal conditions for an outbreak.

So what's different about 2019? We had a relatively mild winter, with only three days at or below 28° F, and a wet spring--both conditions mosquitoes love. But the summer, at least by Dallas standards, has so far been cool. Until this week, the DFW Airport weather station saw only two days over 100° F. By the end of July the area usually has experienced more than seven days over 100° F.

These graphs show 2019 mosquito abundance and Vector Index (V.I.) estimates compared to previous years. Although mosquito numbers are high this year, the V.I. has remained low for both Tarrant (=Fort Worth-top) and Dallas counties (bottom). In 2012 the V.I. exceeded the danger level of 0.5 for multiple weeks (blue dotted line). Source: Tarrant County Public Health and Dallas County Health and Human Services.

Predicting WNV

One of the tools used by health departments to predict disease risk for WNV is a statistic called the vector index (V.I.). The V.I. is calculated weekly from mosquito trap data, and combines information on both average abundance of Culex quinquefasciatus (the main carrier of WNV) and disease incidence in the trapped mosquitoes. A V.I. of 0.5 or higher for two or more weeks is considered a crisis indicator by some health officials.

The graphs shown here are provided by epidemiologists in Dallas and Fort Worth, and show both mosquito abundance and V.I. estimates for both counties. Despite higher mosquito numbers, the V.I. hasn't ventured above 0.1 for either Dallas or Tarrant counties this summer. Most of the season the V.I. has been closer to zero, hence less need for mosquito spraying and fewer people getting sick. In Dallas county this year there have been no human cases of WNV. Tarrant County (Fort Worth) reports only one case this year with a very low V.I., near zero most weeks (top graph).

According to statistics from the Texas Department of State Health Services, low WNV incidence seems to be true for the whole state this year with no reported human cases as of the end of July. Harris County (Houston) also reports a light year for WNV, according to the acting director of Mosquito and Vector Control, Chris Fredregill.

Looking Ahead

With this week's string of 100° days in many areas will risk go up? Certainly West Nile virus remains a threat to all of us through the end of the summer and into the fall; but this late in the season the chance of a major outbreak is probably low. On the other hand, hot weather favors the virus. It's no time to forget about mosquitoes. I expect Aedes mosquitoes (yellow fever mosquito and Asian tiger mosquito) to become more abundant after last weekend's rains. This week is a good time to get out and dump standing water. Although Aedes mosquitoes are not major disease risks, they cause most of the itchy mosquito bites we get during the day--and we don't want that.

Why Surveillance Reports?

Integrated pest management is just as relevant for mosquito control as it is for all other forms of pest control. One of the principles of IPM is to base treatments on pest numbers. Because mosquito monitoring is expensive and requires special expertise beyond what most PMPs possess, few companies monitor mosquito numbers or disease. However, high quality data may be available from your local health authorities, depending where you live. A pest management company can use this data to alert customers to times of higher disease risk and changes in mosquito abundance.

Every community's mosquito situation will be different. If you are doing business in a larger metropolitan area, or a mosquito control district, you may have access to the kind of data shown here. To find out, contact your local or regional health department and ask if they provide reports of mosquito abundance and disease prevalence.

An additional source of information for both PMPs and your customers is the Mosquito Safari website. At the Safari you can take a virtual tour of a field and a backyard and learn important facts about mosquitoes.

If you need more intensive training, our Extension medical entomologist, Dr. Sonja Swiger, is offering classes this year for pesticide applicators wanting to prepare for their Public Health (Category 12) license. In the fall she also offers several 3-day Master Vector Borne Disease Management Courses around the state. To learn more, or to register, go to https://livestockvetento.tamu.edu/workshop-registration/ .

Monday, August 5, 2019

Cockroaches have historically been a top pest and reliable source of business for PMPs. Indeed, from day one most new technicians are taught to recognize the four most commonly encountered species:

the German cockroach--one of our smaller cockroaches, bane of restaurants and homes

the American cockroach (a fast and intimidating insect that looks twice as big as it really is when running across a floor or flying)

the black, rather nasty Oriental cockroach--pest of sewers and the grounds around buildings

the smoky brown cockroach, an outdoor cockroach unafraid to venture into homes.

Other common species, depending on your part of the country, include the Australian, brown, brown-banded, Asian and field cockroaches.

Figure 1. The adult female S. lateralis (A) and adult female Oriental
cockroach (B) are similar in size and color. Arrow points
to the distinguishing light marking on the forewing margin
of the Turkestan cockroach. Photo modified from Kim and
Rust (2013).

In many parts of the country pest management professionals need to add the invasive Turkestan cockroach (Shelfordella lateralis Walker) to their watch list. This Asian invader is quickly making a name for itself and moving through Texas and other states.

Because the Turkestan cockroach looks similar to other species, you may already have seen it and not realized it was something new. Female Turkestans look like Oriental cockroaches. Male Turkestans look like small American cockroaches or perhaps an innocuous field roach.

Spread

The Turkestan cockroach has becoming a significant new pest since it was first reported in Shelford, California in 1978 and El Paso, Texas in 1979. It has since spread through Arizona and New Mexico, across Texas and even to Georgia. This week I got my first north Texas specimen, and tentatively identified an emailed photo from Tennessee as a Turkestan cockroach.

Figure 2. To my knowledge, this is the first Turkestan cockroach
recorded from north Texas. Collected from a hotel in Frisco,
TX (VII-29-2019). Note the pale, almost transparent border
at the margin of the forewing, and the size (28 mm/one inch),
which is smaller than a typical American cockroach. Photo
M. Merchant.

If you think this pest won't reach your area soon, think again. Internet commerce is also at work. Turkestan cockroaches are commonly sold online where they are well known in the pet trade as "red runners." They provide food for reptile, amphibian and small mammals. Pet owners like the fact that Turkestan cockroaches breed quickly, do well in captivity and don't climb glass (so are easy to keep in aquaria).

My first North Texas specimen of a Turkestan cockroach came this week courtesy of Emory Matts, with Rentokil Steritech. Guests at a local hotel recently started complaining of roaches on several floors. Whether this was an invasion from outdoors (males can fly and are attracted to lights at night), or represented an indoor infestation could not be determined. Though it's often referred to as an "outdoor" insect, the Turkestan is capable of establishing itself indoors, similar to Oriental and American cockroaches.

Competition

Figure 3. Turkestan (A) and Oriental cockroach nymphs.
Notice the reddish-brown thorax and dark abdomen of
the Turkestan nymph compared to the uniform brown color
of the Oriental. Photo from Kim and Rust (2013).

According to Kim and Rust (2013), the Turkestan is replacing the Oriental cockroach throughout much of the Southwest as the most important cockroach pest around the outsides of structures. Common breeding sites are similar to those of Oriental cockroaches, including water meter and irrigation boxes, electrical boxes, hollow block walls, cracks and crevices in concrete, compost piles and potted plants. However, it appears that in the warm climates of the Southwest, Turkestan cockroaches rush through their 5 nymph stages faster than the Oriental with its 7-10 nymph stages. A female Turkestan cockroach will produce about 25 oothecae (egg cases) in her lifetime compared to 5-10 oothecae for an Oriental cockroach. The numbers tell the story as to why Turkestan cockroaches are taking over.

Distinguishing Turkestan cockroaches

The immature Turkestan roach resembles both Oriental and American nymphs in general appearance (Fig. 3). The Oriental cockroach, however, is uniformly dark-brown and the American cockroach is uniformly reddish brown. The Turkestan, in contrast, is reddish-brown on the head and thorax (pro- and meso-thorax) and dark-brown only on the rear of the body.

Figure 4. American (top) and Australian cockroaches.
Note the bold markings on pronotum and the
forewings of the Australian cockroach, in contrast
with the American, which lacks forewing markings.
Photos, M. Merchant.

Besides size (the male Turkestan cockroach is smaller), American and Australian cockroaches can be distinguished by both the wing borders and markings on the prothorax (shield behind the head)(Fig. 4). Forewing margins of the Turkestan cockroach are pale and almost transparent compared to the uniform-colored wings of the American, and the bold yellow margins of the Australian. Click here for another image of male and female Turkestans.

Control

Research on control methods for the Turkestan cockroach is still limited; however control methods should be similar as for the Oriental cockroach. Granular cockroach baits can be effective; however, Kim and Rust suggest that higher reproductive and growth rates for the Turkestan cockroach could mean that technicians should need more bait when treating. Special attention should be paid to pest proofing doors and other building entry points to keep cockroaches outdoors where they pose the least trouble.

Friday, March 8, 2019

Entomologists get excited over the strangest things. This morning I got my first bat bug sample ever, and I'm still all aflutter.

The pronotal fringe hairs on these common bed bugs (see arrow) are short, no longer than the width of the bed bug's eye. This feature is visible with a hand-lens even through a plastic zip-loc bag, as inthis photo. Image by Mike Merchant.

Bat bugs and swallow bugs are relatives of the common bed bug, Cimex lectularius--the species you are most likely to encounter on a daily basis in the pest control business. There are approximately 100 species in the bed bug family, referred to as cimicids (sigh MISS ids). Most are specialists on certain types of birds and bats. Generally, these bird and bat feeders have little interest in human blood, and cannot survive without their normal winged hosts.

Most of these other species of cimicid bugs look much like our common bed bug. They will be flat, oval-shaped and reddish-brown, with adult forms about the size of an apple seed.

Current thinking among biologists is that cimicids that specialize in birds and people are spin-offs from ancestral, bat-loving bed bugs. The data suggest that the switch-over from bat feeding to human feeding may not have been that long ago in evolutionary time. It's not difficult to imagine our ancient ancestors scratching from the first hungry bat bugs checking out other food choices in dark caves.

Today, it's rare to find our common bed bug feeding on bats, though it seems this species is less choosy about hosts than most other cimicids. Cimex lectularius has been found feeding on chickens, pigeons, swallows and even pets (though its clearly preferred host seems to be humans).

Distinguishing common bed bugs

Though bed bug identification is definitely a job for specialists, fortunately it's not difficult for any PMP to tell the difference between bat bugs and the common bed bug with a hand lens or office microscope. It has to do with the haircut.

Common bed bugs, our main human bed bug pest, have a fringe of short hairs on the edges of the pronotum, that "shield-like" plate behind the head (see first picture).

The pronotal fringe hairs of bat bugs and most bird bugs (see arrow) are longer than the eye iswide. Image of an eastern bat bug, Cimex adjunctus, by Mike Merchant.

Bat and swallow bug fringe hairs are longer (see lower picture). This shouldn't be hard to remember if you think of bats as being hairier than people. Though this character won't necessarily help you tell a bat bug from a swallow bug or pigeon bug, it is a reliable way to tell one of these non-people feeders from the common bed bug.

Don't walk away

Just because your customer has bat bugs instead of bed bugs, it doesn't mean your job is done. While treating bedrooms with a conventional bed bug treatment is unnecessary (bat bugs do not aggregate around beds, nor reproduce on people), there is still pest control to be done. Bat and bird bugs are best controlled by eliminating their preferred hosts from the structure and possibly treating the roosting/nesting sites for bed bugs.

Host elimination is not as simple as closing entry points for bats or birds. Most birds and all bats are federally protected and cannot be killed, nor active nests destroyed. Instead, they must be excluded at the end of nesting season. If you have questions about bird and bat exclusion, it's best to check with your state wildlife department. Nesting season for protected birds and bats varies from one area to another.

Unlike common bed bugs, it's unlikely that bat bugs and the various bird bugs will exhibit high levels of insecticide resistance. Any of the pyrethroid or pyrethroid-combination insecticides for common bed bugs should provide good control of bat and bird bugs around suspected harborages and entry points into living areas.

Bat bug and swallow bugs are not that common in our business. The sample I received today was, I learned later, collected from a home in Indiana. But if bed bugs are being found in unusual places, especially away from bedrooms, keep in mind that other bed bug species are out there. Remember that pest identification is always the starting point for good pest control. And it can be fun too; ask any entomologist.

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About Me

I have served as entomology specialist for Texas AgriLife Extension since 1989. I get to work with, and for, a bunch of great people including pest management professionals, school facilities managers, extension volunteers, researchers and other extension professionals. My areas of specialty center on research on insects affecting man including spiders, scorpions, fire ants, termites and others. My program also focuses on training school maintenance professionals in principles of integrated pest management (IPM). Our goal is to make schools healthier, cleaner places to study and live.